This invention relates to systems for collecting solar energy and more particularly to improvements therein.
A comparison of solar energy collected by typical non-tracking systems, single-axis systems, and two axis systems is able to harvest 78-80% of the available direct normal radiation, whereas the single axis system collects 30-35% and the non-tracking system collects between 17 and 20%. Of further interest is that the non-tracking systems provide a collection temperature of between 300.degree.-400.degree. F., single axis trackers between 500.degree.-600.degree. F., but temperatures in the range of between 1000.degree.-2000.degree. F. may be easily attained by two axis tracking systems. Thus, from the foregoing, it can be seen that a two axis solar energy collection system is clearly superior. However, the superior performance of the two axis system, unfortunately, is not a determinant as to which system is selected. Such items as initial cost and operating costs, etc. are also taken into consideration. Accordingly, the key to taking advantage of a much higher potential performance of a two axis system is to achieve an initial cost, as well as operating expense levels, which will be less in proportion to the output derived than those from the other systems. Stated in another way, the system which should be selected should be the one that has the lowest cost per kilowatt of electricity derived.